MCP Server

Yaak has an MCP (Model Context Protocol) server plugin that allows AI assistants like Claude, Cursor, and other MCP-compatible tools to interact with your workspaces and send requests.

What is MCP?

The Model Context Protocol is an open standard that enables AI applications to connect with external tools and data sources. With Yaak’s MCP server, AI assistants can:

• List and inspect your HTTP requests
• Send requests and retrieve responses
• Create, update, and delete requests
• Organize requests into folders
• Work across multiple workspaces

Installing the MCP Server Plugin

The MCP server is available as a plugin. To install it:

1. Go to yaak.app/plugins/@yaak/mcp-server and click Install, or
2. Open Settings > Plugins in Yaak and search for “MCP Server”

Once installed, the MCP server starts automatically when Yaak launches and listens on http://127.0.0.1:64343/mcp.

Connecting AI Tools

Claude Desktop

Add Yaak to your Claude Desktop configuration file:

macOS: ~/Library/Application Support/Claude/claude_desktop_config.json Windows: %APPDATA%\Claude\claude_desktop_config.json

{
  "mcpServers": {
    "yaak": {
      "url": "http://127.0.0.1:64343/mcp"
    }
  }
}

Restart Claude Desktop to connect.

Cursor

Add Yaak to your Cursor MCP configuration:

{
  "mcpServers": {
    "yaak": {
      "url": "http://127.0.0.1:64343/mcp"
    }
  }
}

Other MCP Clients

Any MCP-compatible client can connect using the server URL http://127.0.0.1:64343/mcp. The server uses the Streamable HTTP transport.

Available Tools

The MCP server exposes the following tools to connected AI assistants:

HTTP Requests

Tool	Description
list_http_requests	List all HTTP requests in a workspace
get_http_request	Get details of a specific request by ID
send_http_request	Send a request and get the response
create_http_request	Create a new HTTP request
update_http_request	Update an existing request
delete_http_request	Delete a request

Workspaces and Folders

Tool	Description
list_workspaces	List all open workspaces
list_folders	List folders in a workspace
get_workspace_id	Get the current workspace ID
get_environment_id	Get the current environment ID

Utilities

Tool	Description
show_toast	Display a toast notification in Yaak

Example Usage

Once connected, you can ask your AI assistant to interact with Yaak naturally:

• “List all the requests in my workspace”
• “Send the Login request and show me the response”
• “Create a new GET request to https://api.example.com/users"
• “Update the Authorization header on the Get User request”
• “Add a JSON body to the Create User request”

The AI assistant uses the MCP tools to perform these actions directly in Yaak.

Multiple Workspaces

If you have multiple workspaces open, the AI assistant will ask which one you want to use before performing actions.

Troubleshooting

MCP server not starting: Check that the MCP Server plugin is installed in Settings > Plugins. Look for a toast notification when Yaak starts confirming the server is running.

Connection refused: Ensure Yaak is running and the MCP Server plugin is installed. The server only starts after Yaak fully launches.

Port conflict: If port 64343 is in use by another application, the MCP server will fail to start. Check for other applications using this port.

AI can’t find requests: Make sure you have a workspace open with saved requests. The MCP server only sees requests in open workspaces.